The dissemination and playback of media programs has undergone substantial changes in the past decade. Previously, media programs (which may include audio, video, or both) were disseminated either by analog broadcast (conventional, satellite, or cable) or by dissemination of films to movie theaters.
These traditional dissemination and playback means remain in use after the advent of digital technology. However, digital technologies have had a profound effect on the dissemination and playback of media programs. For example, digital technology permitted the use of digital video recorders (DVRs). DVRs, while similar in function to standard analog video cassette recorders (VCRs), provide a number of additional useful functions including live pause, the ability to record one program while playing back another, and the integration of the electronic program guides with DVR functionality (so that the recordation of media programs could be scheduled far in advance).
Digital technology also permitted the dissemination and playback of media programs via the Internet, with improved signal processing. These methods of dissemination and playback have become competitive with traditional means. Dissemination of media programs via the Internet may occur either by simple downloading, progressive downloading or streaming.
For progressive download, a media file having the media program is downloaded via the Internet using dial-up, DSL, ADSL, cable, T1, or other high speed connection. Such downloading is typically performed by a web server via the Internet.
Simple downloading downloads the bytes of the media file in any convenient order, while progressive download downloads bytes at the beginning of a file and continues downloading the file sequentially and consecutively until the last byte. At any particular time during progressive downloading, portions of the file may not be immediately available for playback. In some situations, the entire file must be downloaded first before a media player can start playback. In other progressive download situations, media players are able to start playback once enough of the beginning of the file has downloaded, however, the media player must download enough information to support some form of playback before playback can occur. Playback of progressively downloaded media files is often delayed by slow Internet connections and is also often choppy and/or contains a high likelihood of stopping after only a few seconds. Once a progressively downloaded media program has been completely downloaded, it may be stored on the end-user computer for later use.
Streaming delivers media content continuously to a media player and media playback occurs simultaneously. The end-user is capable of playing the media immediately upon delivery by the content provider. Traditional streaming techniques originate from a single provider delivering a stream of data to a set of end-users. High bandwidth and central processing unit (CPU) power are required to deliver a single stream to a large audience, and the required bandwidth of the provider increases as the number of end-users increases.
Unlike progressive downloading, streaming media can be delivered on-demand or live. Wherein progressive download requires downloading the entire file or downloading enough of the entire file to start playback at the beginning, streaming enables immediate playback at any point within the file. End-users may skip through the media file to start playback or change playback to any point in the media file. Hence, the end-user does not need to wait for the file to progressively download. Typically, streaming media is delivered from a few dedicated servers having high bandwidth capabilities.
Typically, progressively downloaded media is transmitted to the user computer at a rate that is faster than playback. The media program player buffers this data, and may indicate how much of the media program has been buffered by providing an indicator, usually as a part of a “progress bar.” A control is often provided that allows the user to go to any point in the program that has already been buffered by selecting the control and moving it to a different location along the progress bar. This allows the user to randomly access any buffered portion of the media program.
Streaming media players generally do not rely on buffering to provide random access to any point in the media program. Instead, this may be accomplished through the use of control messages transmitted from the media player to the streaming media server. Consequently, when a user wishes to move to a particular point in a program (e.g., such as by moving along the progress bar or slider), the program may be paused while the request from the user is processed. During the program pause (e.g., while the user is trying to manipulate the program), the slider or progress bar will often show images that have been pre-assigned or tagged as indicative of a chapter in the media program, however these tagged or chapter images are not necessarily accurate in time to the particular point in the program the user wishes to view.
Adaptive Bit Rate (ABR) streaming is a technology that combines aspects of streaming and progressive download to provide streaming of media content by breaking the content into a sequence of small HTTP-based file segments, each segment containing a short interval of playback time of a content that is potentially many hours in duration, such as a movie or the live broadcast of a sports event. An ABR player provides streaming playback by requesting an appropriate series of segments as determined by a manifest or playlist file and user requests, such as play, pause, rewind, etc. For example, the user may use HTTP Get or Byterange requests to obtain such media segments.